LONDON (Reuters)
- A British drug company said on Wednesday it was a step closer to launching
a cannabis-based medicine for patients with multiple sclerosis and other
conditions that cause severe pain.

GW Pharmaceuticals
said it had obtained encouraging results from the latest phase of clinical
trials and was now extending its programme into Phase III trials, which
involve a wider range of patients in new locations. The studies are the
last hurdle before approval is granted.

The company said
it had also obtained regulatory approval to start clinical trials in Canada.

Sufferers from diseases
such as multiple sclerosis, which attacks the central nervous system, have
been calling for a pain-relieving cannabis medicine for years and many
have broken the law by buying the drug from street dealers.

GW has invested 12
million ($17 million) in its research and hopes to market its first prescription
cannabis-based medicine in 2003.

It will offer patients
the pain-relieving benefits of cannabis without what the company calls
``unwanted psychoactive side effects.'' Getting ``high,'' as would happen
if patients smoked marijuana, does not in itself offer medical benefits.

GW's trials have
involved patients taking cannabis-based medicine by spraying it under their
tongues, which allows it to be absorbed rather than swallowed.

``We are seeing a
significant improvement in quality of life for sufferers of a range of
medical conditions and look forward to extending the trials programme.''

Results appeared
to show significant reduction in pain, muscle spasm and bladder dysfunction
as well as improved neurological function.

Guy said the company
had received approval from Canadian health authorities allowing it to start
trials in Canada.

GW Pharmaceuticals
Ltd is a private company, set up in 1997, which operates under licences
issued by the British Home Office (interior ministry) to cultivate, possess
and supply cannabis for medical research.

The company has been
growing cannabis in secure, computer-controlled glasshouses in southern
England.

The plants are the
same as those grown for recreational use, but trials are designed to maximise
the drug's analgesic, or pain-relieving, effect rather than to make subjects
so high they do not care about the pain.

The company said
that if health authorities issued a licence for cannabis-based medicine,
the government had indicated it would be willing to amend narcotics laws
to allow it to be prescribed.